Clock



FIG. 1 is a front elevational view of a clock showing my new design;

FIG. 2 is a rear elevational view thereof;

FIG. 3 is a right side elevational view thereof, the left side being thesame in appearance as the right side; and

FIG. 4 is a top plan view thereof, the bottom being the same inappearance as the top.

The ornamental design for a clock, as shown and described.